Lock-nut



2 Sheets sheet L F- H- Howlgs-l L00K NUT. i

, Paten l l l @MQW WQW.

UNITED {STATES- PATENT OFFICE.

FRANK n. HoWEs, on EAST ORANGE, NEW JERSEY.

LOCK-NUT.

SPECIFICATION forming part of Letters Patent No. 361.289, dated April 19, 1887.

Application filed November 17, 1886. Serial No. 219.161. (No model.) l

having a ratchet-thread whose pitch is tento` the inch-with a nut having a ratchet-thread whose pitch is nine and six-tenths to the inch.

The invention also embraces the employment, in a bolt and nut provided with ratchet.- threads which are respectively of `uniform but relatively of different pitches, of a ratchet-l thread in the nut the vangle of the narrow side of which is different from the angle of the narrow side of the bolt-thread.

The object of this invention is to produce,

solely by the interaction of the bolt and n'ut,

a gradually-increasing interference of their4 threads with each other, so'that while the nut can be easily started on the bolt and can be freely turned one, two,or more revolutions, as may be arranged, the ultimate effect of the continued turning of the nut upon the bolt will be the bending backward of some of the threads by the impact of their narrower sides upon each other, whereby the angles of their narrower sides with their longer sides will become less acute, and not only will the nut thus be jammed upon the bolt, but it will be incapable of removal, except by the continued application during such removal of force sufficient to overcome the increased friction resulting from the variably-distorted conditions of those 1 ofthe threads whichhave been engaged with each other. v n

The jamming of a nut upon a bolt has heretofore beeneffected by making the bolt-thread or the nut-thread of gradually-changing pitch, and it has also been effected by making the threads of the nut and bolt, respectively, of different shapes in cross-section, 'but of like pitch.

In the present invention the threads of the nut and bolt are each made of uniform pitchv throughout, but the pitch of one is made to differ in a prescribed degree from the pitch of the other, and such difference is calculated 55 with reference to the number of revolutions which the nut is required to turn before being broughthome against the obj ect through which the bolt is inserted, so that by the time the nut has been brought to its ultimate position 6o there will have been such an extent of interference of the threads of the nut with those of the bolt as will have produced the desired upsetting of the threads,whereby the jamming of the nut upon the bolt is effected without dependence upon the impact of the nutagainst the face of the object through which the bolt is inserted.

The accompanying drawings of bolts and nuts, illustrating the invention, are as follows,

viz: e

Figure 1 is a longitudinal section of a bolt and nut the ratchet-threads of which are alike in form. Fig. 2 is a section of the nut, showing the original shape of the nut-thread. Fig. 7 5

3 is a longitudinal section of a bolt and nut provided with so-called gript-hreads-. e., ratchet-nut threads and bolt-threads, which differ from each other in form in respect of the angles of their narrower sides to the axis of 8o v the bolt.

For convenience of illustration,the drawings are made to represent threads of excessively coarse pitch; but in practice a threequarter-inch bolt will be provided, for example, with a thread of ten to the inch, and its nut with a thread of nine and six-tenths to the inch.

Fig. 1 represents a bolt, A, the shank of which is provided with a ratchet-thread, a. 9o As originally formed, the narrow side of the thread is perpendicular to the axis of the bolt, the entire thread originally having the shape in cross-section of the four convolutions 1, 2, 3, and 4, which in Fig. l are represented as above the part of the bolt over which the nut B has been forced. Similarly, all the convolutions of the original nut-thread b are formed with their narrower sidesfb b', &c., perpendicular to the axis of the nut.

The character of the effect produced by the interaction of bolt and nut threads of coniiicting pitches' is illustrated in Fig. 1, in which, as will be seen, the apices of those of the con-'f ICO volutions of the bolt-thread over which the axis of the bolt. Thus either the'bolt or thc nut has passed are, in variable degrees, tipped nut may be originally provided with an underdownward, and the apices of those of the concut thread-4er example, like the undercut volutions of the nut-thread which have passed thread C (shown in Fig. 3)-in that part of the 5 over the bolt are, in variable degrees, tipped shank C' of the bolt D over which the uut E upward. There is thus effected a gradual has not passed, in which case the nut may be change in the angles of the narrow sides of the provided with a ratchet-thrcad whose shorter convolutions of the thread with the axis of the sides are either perpendicular to the axis of 7J- bolt. The narrow side of the convolution 5 of the bolt or are inclined thereto in a less deio thebolt-thread and thenarrowsideofthecouvogree than, or in the opposite direction f om,

lution 5"of the nutthread are slightly inclined the shorter sides of the bolt-threads. outwardly and downwardly, asshown in Fig. l; It results from the diierencein thercspec tive the convolution 6 of the bolt-thread and the angles of the shorter sides of the two threads 8c convolution 6 of the nut-thread are a little that when the nut E is first applied tothe bolt 1 5 more inclined; the convolution 7 of the bolt- D the only parts of the shorter sides of the thread and the convolution 'bof the nut-thread two threads which bear upon each other are are farther inclined, the remaining convoluthebase of the nut-thread and the apex: c "the tions, 8, 9, 10, 11, and 12, of the bolt-thread boltthread, and that there is left between the B5 being still more inclined, and the remaining shorter sides of the two threadsavacan space, zo convolutions, 8, 9b, and 10", of the nut-thread` d d d, dac., which is triangular in crossi l ion. being also still more inclined. A It follows that the progression of the n t upon The extent of the changes in the angles of the bolt does not at first distort the nut-th read,

A3c the bolt-thread and upon the nut-thread; of the bolt-thread bent backward so far that the narrow sides of the convolutions of the but does distort the holt-thread, the apic'es of go thread is purposely magnified in Fig. l in the engaged convolutions of the bolt-th read order to more clearly illustrate the character only being bent backward; hence only a comof the eiiect produced by the interference of a paratively moderate force will be required to ratchet-thread of coarse pitch in the nut with turn the nut E upon the bolt D in the act of a ratchet-thread of finer pitch on the bolt. applying the nut to the bolt until the nut has t This effect is produced progressively both upon been turned so many revolutions and the apices hence the upper convolutions of tl1e` nutthe apices of the convolutions ofthe nut-thread thread are less distorted from their original are brought into contact with the narrow sides angles than the lower convolutions are; and it ofthe convolutions of the boltlthread.` The ic i therefore follows that when the nut has been number of revolutions of the nut required to screwed on to the bolt to the position which it bring about such contact will of course vary is intended to occupy, as illustrated in Fig. 1, with the width of the spaces between the narthe upper convolutions of the nut-thread do row sides of the boltand nut threads. lf there not have the same angles upon their sides as is only a slight difference between the angles the lower convolutions, and hence the upper ofthe narrow sides of the bolt and nut threads 40 convolutions of the nut-thread will not ft those those spaces will of course be narrow, and a convolutions of the bolt-thread which are at less number of revolutions ofthe nut will close the time engaged by the lower convolutions them up. If the difference between the angles of the nut-thread. Therefore the nut', having of the narrow sides of the bolt and nut threads 11o been screwed on to the desired position, eanis greater, then the spaces will be wider, and

not be unscrewed without the application to the nut canin that case be turned a greater it of suiicient force to again upset the threads number of revolutions before the apices of the both of the nut and bolt. convolutions of the nutthread will be brought 1t will be obvious thatv the base or root of a into collision with the narrower sides of the 115 ratchet-thread is much stronger than its apex convolutions of the bolt-thread. In View of 5c in respect of its capacity to resist strains in these considerations, the difference between directions parallel with the axis of the bolt. the angles of the narrow sides of the bolt and It will therefore be understood that the eectnut threads can be proportioned with referiveness of the interaction of the bolt and nut ence to the number of revolutions which it is 12o in producing the gradual distortion and jamdesired the nut shall be capable of making bcming of the threads shown and described is fore completely closing up the spaces between greatly promoted by the ratchet forms of those lthenarrow sides of the bolt and nut threads; threads, from which it results that the apices, and it will be seen that provision may be made which are the weakest parts of the threads, for screwingr on the nut to the position which 125 bear upon the roots or bases, which are the itis intended to ultimately occupy, either with strongest parts ofthe threads. or without fully closing the spaces between Fig. 3 illustrates the employment of the the narrow sides of the convolutions of the broad feature of the invention in connection bolt and nut threads. withV so-called gripbolts, the peculiarity of It will be understood that thc term ratchet- 1 4o which is that the angle of the shorter sides-of thread herein used is intended to compre- 6 5 the nut-threads with relation to the axis of the hend any form of screw-thread whose shape bolt is different from the angle of the shorter in cross-section is such that one side is longer sides of the bolt-threads wit-h relation to the than the other side.

What is claimed as the invention is I .A with a nut provided with a ratchet-thread of 1.l The combination, as herein-set forth',` of a diierent uniform pitch, the narrow side of a screw-bolt provided with a ratchet-thread-ot' which nut-thread is formed at an angle with prescribed uniform pitch withfa nut provided the axis of the nut, which is different from the 5 with a ratchet-thread of a diii'erent uniform angle of the narrow side of the bolt-thread to I5 pitch. the axis of the bolt.

2. A screw-bolt provided with a ratchet- FRANK H. HOWES. thread of prescribed uniform pitch,the narrow XVitnesses: side of which thread is formed at a prescribed M. L. ADAMS,

lo angle with the axis of the bolt, in combination R. C. HoWEs. 

